Regarding GlowDateTimeSelector plugin issue

We are upgrading from ver 10.3  to ver 12.0.1.15778 and we are finding issue in the "GlowDateTimeSelector plugin issue". In ver 12.0.1.15778, the calendar icon is not rendering. It should render as the below screen but it does not appear in the latest version but we have this feature in ver 10.3. Kindly provide your guidance/support to resolve this.